Rotary packing for elastic-fluid turbines.



No. 792,131. PATENTED JUNE 13, 1905. F. HODGKINSON.

RGTARY PACKING FOR ELASTIC FLUID TURBINES.

APPLICATION FILED 113.10. 1905.

UNITED STATES Patented June 13, 1-905.

PATENT ()FFICE.

FRANCIS HODGKINSON, OF EDGEI/VOOD PARK, PENNSYLVANIA, ASSIGNOR TO THEWVESTINGHOUSE MACHINE COMPANY, A CORPORATION OF PENNSYLVANIA.

ROTARY PACKING FOR ELASTIC-FLUID TURBINES.

SPECIFICATION forming part of Letters Patent No. 792,131, dated June 13,1905.

Application filed February 10, 1905. Serial No. 245,167.

To all whom it may concern:

Be it known that I, FRANCIS HODGKINSON, a subject of the King of GreatBritain and Ireland, residing at Edgewood Park, in the 5 county ofAllegheny and State of Pennsylvania, have invented a new and usefulImprovement in Rotary Packing for Elastic-Fluid Turbines, of which thefollowing is a specification. This invention relates to packing forrotary I shafts or spindles, and more particularly to means for packingthe shafts or spindles of elastic-fluid turbines or compressors.

Many difliculties have been encountered in producing packings for theshafts or spindles of elastic-fluid turbines and compressors, as theconditions are somewhat peculiar. The shafts or spindles of this classof machines are liable to and do distort, and for this reason a perfectalinement cannot be maintained. The differences in pressure between theinterior and exterior of the casings of these machines make a tightjoint between the shafts and the casing at that point where the shaftsextend through the casing necessary, and the high 5 speeds of rotationencountered make it impossible to pack the shaft as heretofore donewhere relatively low speeds are encountered. An object of this inventionis to provide a packing applicable to this class of machine 3 which willeffectually pack against considerable differences in pressures betweenthe opposite sides of the machinecasing2 6., a packing which willprevent the escape of fluid from the interior of the casing if thepressure on the interior is greater than atmospheric pressure and willpack against atmospheric pressure if the pressure at the interior of thecasing is less than atmospheric pressure, as where a turbine is runningcondensing and the 4 interior is connected to a condenser.

A further object is to provide such a packing as above outlined in whichthe friction is negligible.

These and other objects I attain by means of the device illustrated inthe single sheet of drawings accompanying this application and forming apart thereof and throughout the two views of which similar elements aredenoted by like characters.

As the invention is equally applicable to turbines or compressors or toany other machines in which like conditions are met, shaft 1 mayrepresent the shaft of any such machine. The shaft extends through theexterior casing, which in turbines, as is now common, is divided on thehorizontal plane through its aXis. The fragment shown of the upper halfof the casing is numbered 2 and the fragment of the lower half 3. Thetwo halves of the casing meet in a finished joint, and the end wall ofthe casing thus formed by the two halves is provided with a channel orcylindrical chamber 4, concentric with the geometric axis of theshaft 1. A collar 5, preferably formed of non-rusting metal, such asbronze, is shrunk on or otherwise secured to that portion of shaft 1lying between the opposite sides of the end Wall of the casing. Collar 5is provided with an annular flange 6, to which a runner 7 is bolted orotherwise rigidly secured. The outer periphery of the runner 7 isprovided with a circumferential groove or recess 8, which incross-section is preferably half-round, and the opposite faces of therunner are provided with blades or paddles 9, preferably disposed asillustrated in Fig. 2. Clearance is left beyond the periphery of therunner and the outer ends of the blades or paddles and the innerperipheral wall of the annular chamber 4, which surrounds the runner.Sufficient clearance is left between the sides of the blades or paddlesand the side walls of the chamber 4 to allow for longitudinal adjustmentof the shaft or slight longitudinal play.

Collar 55 on each side of the runner is provided with a multiple numberor series of annular flanges or ridges 10, and each of the halves of thecasing is provided with a semicircular member 11, bolted or otherwisesecured to the casing and provided with grooves or depressions 12, whichspan the annular ridges 10. lVhen the two halves of the casing are inposition, as shown in Fig. 1, these annular ridges 10 and thedepressions 12, which become annular when the halves of the casing aretogether, form an interleaving gland or packing, which hereinafter willbe referred to as the supplemental or auxiliary packing.

A duct or passage 13, formed in any suitable manner, leads into thelower part of the chamber 4, preferably in line with the groove 8 of therunner, and through this duct or passage the chamber 4 is supplied withsuitable sealing liquid, such as water, from any suitable source ofsupply. A passage lat leads away from chamber 4 at its top, andpreferably in line with passage 13.

If the packing device is applied to a steamturbine runningnon-condensing, then the gland is liable to become so hot that the waterused for the seal will boil, and passage 14 is utilized for the escapeof the steam generated, as well as for the passage of water, as it hasbeen found advisable when running noncondensing to maintain a continuousflow of water through the passages 13 and 14 and the chamber 4.

As ordinarily employed for use in turbines and compressors passage letwill be connected with a pipe suitable for maintainingaconstant head,and this head, which it may be desirable to have adjustable, willdetermine the resistance to the pressure created by the run ner. Therunner rotating in the direction indicated by the arrow in Fig. 2 willmaintain an annulus of sealing liquid in the outer portion of chamber 4,which annulus, of course, will extend farther down on the side of therunner nearest the side of lowest pressure 41. a, if the pressure withinthe machine is greater than the pressure outside of the machine theannulus will be deeper on the outside of the runner, and vice versa.

hen steam-turbines are running condensing, it is sometimes desirable tomaintain the vacuum within the casing while the turbine is at rest, andtherefore the supplemental or auxiliary packings formed by theinterleaving glands are utilized.

It is evident that if the collar and easing on each side of the runnerwere of smooth bore and the flow of water or other sealing liquid intothe gland were maintained while the turbine was at rest the interior ofthe turbine would be flooded. The water under the influence of itsstatic'head and the suction caused by the partial vacuum would flowunrestricted through the shaft clearance-space.

It is known that the energy of astatic head is partially and sometimeswholly consumed by friction introduced by turns and twists in and thesize and length of passages designed for its conveyance from one placeto another, and I have applied this in reducing toa minimum the amountof sealing fluid necessary when the turbine is at rest.

On the rotating shaft, at either side of the centrifugal sealing orpacking device, I have introduced the annular collars, consisting, asoutlined, of a number of alternate grooves and ridges which interleavewith reverselyformed grooves. and ridges formed in the member 11, andthe water or fluid entering the annular chamber 4 must pass through thecircuitous route in order to leak therefrom into the turbine-casing orout into the air.

The clearance between the interleaving collars is small, and theintroduction of the grooves and ridges considerably multiplies thesurface and increases the length of passage through which the water mustflow, thus producing additional resistance to such flow and considerablydecreasing, if not wholly restricting, it.

Even in the absence of liquid packing fluid the interleaving serrationsof the auxiliary packing-collars by the circuitous or tort-nous pathpresented and the friction thus introduced materially resist andthrottle the flow of motive or other fluid through said packing.

The details of construction of this packing device can of course bevaried to suit the case in hand. The runner 7 may have vanes of anydesired shape on one or both sides. It might also be found advisable touse more than one of such runners in packing a joint. The auxiliarypacking-collars can of course be varied in their details and mounting.The grooves and ridges 10 and 12 can be of any desired shape or of anydesired number.

Having thus described my invention, I claim 1. In combination with arotatable shaft provided with a bladed runner, a casing provided with acylindrical chamber for said runner, sealing liquid retained in theouter portion of said chamber by the rotation of said runner, and aninterleaving gland on each side of said chamber between said casing andsaid shaft.

2. In combination with a turbine-casing and a rotatable shaft extendingtherethrough, two separated interleaving glands between said casing andsaid shaft, and a rotatable liquid sealing device between saidinterleaving glands.

3. In combination with a casing and a shaft extending therethrough, twointerleaving glands between said casing and said shaft, a chamber insaid casing between said interleaving glands, a runner mounted on saidshaft Within said chamber and sealing liquid retained in the outerportion of said chamber by the rotation of said runner.

4. In combination with a casing and a rotatable shaft extendingtherethrough, a serrated gland between said casing and said shaft, achamber in said casing surrounding said shaft, a source of supply ofsealing liquid in communication with said chamber, and a run- 1ercarried by said shaft within said chamber whereby during the rotation ofsaid shaft said .iquid is caused to rotate.

5. In combination with a rotatable shaft provided with a bladed runner,a casing provided with a cylindrical chamber for said runner, sealingliquid retained in the outer portion of said chamber by the rotation ofsaid runner, and a packing-gland between said casing and said shaft.

6. In combination with a rotatable shaft provided with a bladed runner,a casing provided with a cylindrical chamber for said runner, sealingliquid retained in the outer portion of said chamber by the rotation ofsaid runner, and an interleaving packing-gland between said casing andsaid shaft.

7. In combination with a rotatable shaft provided with a bladed runner,a casing provided with a cylindrical chamber for said runner, sealingliquid retained in the outer portion of said chamber by the rotation ofsaid runner, and an interleaving liquid packinggland between said casingand said shaft.

8. In combination with a rotatable shaft provided with a bladed runner,a casing provided with a cylindrical chamber for said runner, sealingliquid retained in the outer portion of said chamber by the rotation ofsaid runner, and a tortuous passage between said casing and said shaft.

9. In combination with a rotatable shaft provided with a bladed runner,a casing provided with a cylindrical chamber for said runner, sealingliquid retained in the outer portion of said chamber by the rotation ofsaid runner, and an interleaving packing-gland on each side of saidchamber between said casing and said shaft.

10. In combination with a rotatable shaft provided with a bladed runner,a casing provided with a cylindrical chamber for said runner, sealingliquid retained in the outer portion of said chamber by the rotation ofsaid runner, and a tortuous-passage water-gland on each side of saidchamber between said casing and said shaft.

11. In combination with a rotatable shaft provided with a bladed runner,a casing provided with a cylindrical chamber for said runner, sealingliquid retained in the outer portion of said chamber by the rotation ofsaid runner, and a tortuous-passage packing-gland on each side of saidchamber between said casing and said shaft.

12. In combination with a turbine-casing and a rotatable shaft extendingtherethrough, two separated packing-glands between said casing and saidshaft, and a rotatable liquid packing device between said twopackingglands.

13. In combination with a turbine-casing and a rotatable shaft extendingthrough one end thereof, two separated tortuous-passage packing-glandsbetween said casing and said shaft, and a rotatable liquid packingdevice between said packing-glands.

In testimony whereof I have hereunto subscribed my name this 7th day ofFebruary,

FRANCIS HODGKINSON. IVitnesses:

DAVID VVILLIAMs, JNo. S. GREEN.

